1. Field
The present disclosure relates to a method and a system for determining a location on an image bearing surface of an image printing system where a toner image is to be printed.
2. Description of Related Art
For streak correction in an image printing system, it is important to know with as much certainty as possible where toner images are physically placed on an image bearing surface (e.g., a photoreceptor belt or drum) of the image printing system. One of the prior art approaches was to determine how many “machine clock” counts the toner images are offset from the belt hole. The term “machine clock” refers to a counter or other device that monitors the incremental movements of the belt. Each time a machine clock signal is counted, that indicates movement of the image bearing surface by the applicable increment. However, for various reasons, there can be a difference of up to several machine clock counts between what the offset is thought to be, and where the offset actually is. This difference degrades the quality of the streak correction.
In some image printing systems, a belt hole is used as a reference to determine accurate, reliable start locations for calibrations and clean image bearing surface scans. These start locations for calibrations and clean image bearing surface scans were determined by another subsystem, and transmitted to the image printing system, but this method of determining and transmitting the start locations for calibrations and clean image bearing surface scans is often not highly accurate or reliable. Further, the regions on the image bearing surface that are used during calibration cannot be reliably identified by an exact machine clock signal because the machine clock and belt hole clock are asynchronous.
The inventors have recognized that it would be desirable to provide a method to synchronize the image bearing surface and toner image readings in the image printing system so that calibration can be done accurately for streak detection in the image printing system.